Means for transforming direct current.



l. LANGMUIR.

MEANS FOR TRANSFORMING DIRECT CURRENT.

APPLICATION FILED DEC.29. 1913.

11 w fi fio Patented July 23, 1918.

2 SHEETSSHEET 1.

Witnesses: Inventor:

, Lmu ir His I. LANGMUIR.

MEANS FOR TRANSFORMING DIRECT CURRENT.

APPLICATION FILED DEC-29,1913.

1 27 8 5260 Patented July 23, 1918.

2 SHEETSSHEET 2.

Inventor": Ir-"vin 6 Langmu *r';

UNITED STATES PA 3:.

nor ram. 1

IRVIN G LANGMUIR, OF SCHENECTADY, NEW YORK,

COMPANY, A CORPORATION OF NEW YORK.

ASSIGNOR T0 GENERAL ELECTRIC MEANS FOR TRANSFORMING DIRECT CURRENT.

ne'aaeee.

Application filed December To all whom it may concern:

Be it known that I, IRVING LANGMUIR, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain newand useful Improvements in Means for Trans-- forming Direct Current, of which the following is a specification.

My invention relates to the transformation of a direct current of a given voltage into a direct current In carrying my invention into practice I make use of an energy storing device arranged in cooperative relation with electron discharge tubes. By the term electron discharge tube 1 mean to imply the use of a highly exhausted envelop containing at least two electrodes one of which is provided with means for causing it to emit electrons. A device of this nature when connected to a source of current operates selectively in such a manner as to allow current to How between the electrodes in only one direction; that is, there will be a flow of negative elec tricity from the electron emitting electrode to the other electrode or electrodes, but no flow in the opposite direction. In order that this result may be obtained when a potential of more than 20 or 30 volts is applied it is necessary to have the highest possible exhaustion of the envelop. Otherwise there will be a heavy ionization of the gas present and this will render the device useless for my purpose. By improved methods of exhausting the envelop, however, such a high vacuum may be secured that for any voltage which is applied there is no appreciable gas ionization but the flow of current 1s the result of a pure electron discharge and 1s entirely independent of any gas conductivity.

. If a negatively charged conducting body is placed in the proximity of the electrodes in such an envelop the flow of current will be impeded, and if the negative potential is made high enou h the flow may be stopped altogether. y associating an electron discharge tube having a conducting body interposed between the electrodes and one without such conducting body,with an Specification of Letters Patent.

of a different voltage,

Patented July 23, 1918.

29, 1913. Serial No. 809,247.

energy storing device, I have produced an organization such that the current interrupting action and the selective action of the electron discharge tubes so control the storing and restoring of energy of the energy storing device as to produce in one of the circuits of the system a direct current potential differing from that of the original source.

The novel features which I believe to be characteristic of my invention I have pointed out with particularity in the claims appended hereto. The invention itself, however, both as to the details of its organization and its mode of operation will be better understood by reference to the following description taken in connection with the accompanying drawing in which Figure 1 show diagrammatically one way in which my invention may be carried into effect; Fig. 2 shows a modification thereof, and Fig. 3 shows a system made up of a plurality of transforming devices like that shown in Fig. 1.

In carrying out my invention as illustrated in Fig. 1 the direct current, the voltage of which is to be changed is supplied by the direct current mains 1 and 2. The energy storing device which I use consists of an inductance coil 3 which is connected, to the main 2 having a positive potential and the anode 4 of the electron discharge tube 5. The cathode 6 of this tube is connected to the main 1, which has a negative potential. Interposed between the anode and the cathode is a conducting body 8, preferably in the form of a grid, which is connected to an alternating current source of potential 9. Thecathode is preferably of filamentary form and is provided with heating means consisting of a local battery 10. While the heating of the cathode is the means preferably employed for causing it to emit electrons, other methods may be used to accomplish the same result. If the cathode 6'is heated and the grid 8 is at zero potential there will be a flow of negative electricity from the cathode to the.anode. If the grid is given a positive charge this flow will increase, while if the grid is given a negative .charge the flow will be cut down or interrupted entirely depending upon the voltage applied to the device and the value of the negative charge on the grid. In some cases it will be found desirable also to employ an extra battery 11 in order to impose 795,609, filed an extra negative potential on the grid. For a further description of the causes for and the nature of this phenomenon reference is had to my copending applications Ser. No. October 16, 1913, renewed as application Serial No. 84,241on March 14,

19-16, and 795,610 filed Oct. 16, 1913, re: newed as application Serial No. 84,242 on March-14, 1916.

The inductance coil 3 is also connected to the conductors 12. and 13 of a secondcircuit which includes the electron discharge tube 14. This electron discharge tube has an anode 15 and a cathode 16 with a local battery 17 for heating the same.

9 The energy thus medium may consist partly or entirely of iron. Before the current builds up to its maximum value-however, the alternatin current "source 9 changes the potential of t e grid .8

to negative and. the current is interrupted. The energy stored up in the medium surrounding the coil 3 is then returned andis discharged into the circuit 12-1t-313.

cannot return to the first, as current can flow in onlyone direction through the electron discharge tube 14. It will be seen that by this means a succession of impulses of current is delivered to the second circuit. The firlequency of these impulses will depend upon t c all be in'the same direction. By giving these impulses a high enough frequency and by inserting a condenser 18 between the conductors 12 and 13, I am able to secure a unidirectional and continuous current of constant voltage in the second circuit. The voltage of'the current delivered to the second circuit will depend upon the resistance of that-circuit. It will 'by connecting, several transforming devices in parallel. as shown in Fig. I alternating current sources slightly in phase relation I may deliver a practically continuous successsion of current In order rent from one volta e to another which con- 9 which differ imgulses to the second circuit. to

a condenser. 19 may be connected across the I suppl mains 1 and 2.

In ,ig. 2 I have-shown a modifi c'ation of the grid 8 I to the grid If comparatively low fre-' given'to the second circuit in carrying out frequency of the source '9, but they willalso be apparent that 3 and utilizing" ecrease the time required for the current v r in the coil 3 to'build up to the desired valuethe means used forinterrupting the flow of current in. the first circuit. In place of the alternating current source used. for exciting may emplo' positive terminal of which is connected to the grid through a high resistance 21 and the negative terminal of which is connected by means of a key 22. An-intermediate point nected to' the cathode 6. When the key 22 is open thegrid 8 will be chargedwith a positive potential and current will flow through the tube. As soon asthe key. 22 is closed, ;h'owever, the grid is connected directly't'o the negative ole of the battery and the current through the tube is immediately a battery 20, the i i of the battery is also coni interrupted. In some cases this mode of operation. will be more desirable than the one shown in Fig. 1 because of the fact that the interruption of the current may be accomplished more quicklythan when an alter" nating .citin current source is employed for exthe grid. It will of course be understoo that in place of the battery 20 I may use any source of direct current of the desired' voltage and also that in practice some form of automatic make and break device will beused instead of the key 22. .The high resistance-21 is used to'p'rev'ent the short circuiting of the'battery when the ke is closed.

While I havev shown only two orms of a system for transforming direct current from one voltage to another it will be apparent that many modifications thereof may be made without departing from the scope of my invention; for example, I may use a sec-; ond inductance in the second circuit, placed in inductive relation to the coil 3 for deliv+ .ering the stored up energy to the second circuit.- Other forms of electron discharge tube than those indicated may be employed my invention; for example a tube having a plurality of anodes and a plurality of grids such as that shown and described in m 797,986, fi ed Oct, 27, 1913. I

Certain novel features of lectron discharge devices-and their operation are described and claimed Serial No. 876,132, filed December 10, 1914..

Although certainaspects of the invention described and claimed in the applications mentioned are also described .inEjthe present sists in causing uni irectional'current of one voltage toflow rupting the flow between, said electrodes and copending application Ser.

by me in the abovementioned. applications, and in application Letters" Patent of the United States is between electrodes in-a vacu- 1 um in a circuit containing inductance, int'er- 1 dischargin the stored up energy of the inductance into a second circuit as unidirectional current at a diflerent voltage.

2. The method of transforming direct current from one voltage to another which consists in causing current of one voltage to fiow between electrodes in a vacuum in a circuit containing inductance, interrupting the flow between said electrodes by imposing a negative potential upon a grid placed between them and discharging the stored up energy of the inductance into a second circuit at a different Voltage.

3. The method of transforming direct current from one voltage to another which consists in causing a direct current of a given voltage to'fiow in a circuit comprising an energy storing device and an electron discharge tube, alternately applying positive and negative potentials to a grid placed be tween said electrodes to intermittently store up energy in the energy storing device and deliverin said energy to a second circuit as a uni irectional current of a diiferent voltage.

4. Means for transforming direct current from one voltage to another comprising an inductance common to two circuits, an electron discharge tube in one circuit, means for producing a flow of current through said tube and thereby storing up energy in the inductance, means for interrupting the flow of current through said tube, and means for discharging the stored up energy of the inductance into the second circuit.

5. Means for transforming direct current from one voltage to another comprising an inductance common to two circuits, two electrodes in the first circuit in a highly evacuated envelop, a conducting body interposed between said electrodes, means for imposing negative and positive potentials upon said conducting body, means forstoring up energy from the first circuit in the inductance and discharging said stored up energy in the second circuit, and means to prevent energy discharged into the second circuit from returning to the first.

6. The combination of a source of direct current of a given voltage, an electron discharge tube in circuit with said source and means cofiperating with said device for producing a direct current of a voltage difierent from that of the source.

7. The combination of a source of direct current of a given voltage, an energy storing device, an electron discharge tube in circuit with said source and means coiiperating with said energy storing device and said tube for producing a direct current of a voltage difierent from that of the source.

8. The combination of a source of direct current of a given voltage, an energy storing device, an electron discharge tube, a grid 7 negative between the electrodes of said tube, means for imposing positive and negative potentials on said grid and means cooperating with said energy storing device and said tube for roducing a direct current of a voltage difierent from that of the source.

9. Means for transforming direct current from one voltage to another comprising an inductance common to two circuits, an electron discharge tube in one circuit, means for interrupting the flow of current through said tube and a device in the second circuit having asymmetric conductivity through which stored up energy of the inductance may be discharged into the second circuit.

10. Means for transforming direct current from one voltage to another comprising an inductance common to two circuits, an

. electron discharge tube in one circuit, means for interrupting the flow of current through said tube and an electron discharge device in the second circuit through which stored up energy of the inductance may be discharged into the second circuit.

11. Means for transforming direct current from one voltage to another comprising an inductance common to two circuits, an electron discharge tube in the first circuit comprising an anode, a cathode and a conducting body interposed between anode and cathode inclosed in a highly evacuated envelop, means for imposing alternately positive and negative potentials upon ing body, and a device in the second circuit having asymmetric conductivity through which stored up energy of the inductance may be discharged into the second circuit.

12. Means for transforming direct current from one voltage to another comprising an inductance common to two circuits, an electron discharge tube in the first circuit comprising an anode, a cathode and a conducting body interposed between anode and cathode inclosed in a highly evacuated envelop, means for imposing alternately positive and negative potentials upon said conducting body and an electron discharge device in the second circuit.

13. The combination of a source of direct current of a given voltage, ing device, an electron discharge tube comprising an anode, a cathode and a conducting body interposed between said anode and cathode inclosed in a highly evacuated envelop, means for impressing positive and potentials upon. said conducting body and means cooperating with said energy storing device and said tube for producing a direct current of a voltage difierent from that of the source.

14. The combination of a source of direct current of a given voltage, an energy storing device and an electron discharge tube in a circuit with said source, said electron dissaid conductan energy stor- I a f 1,273,626

fcharge tube cem irising a catliode ananode In witness whereof, I have hereunto set and a conducting body interposed between my hand this 27th dayofDeCember, 1913.

anode and cathode, means for impressing positive and negative. pqtentials upon said conducting body, and a, second circuit eem- Witnesses: prising the energy storing device and a WILLIAM C; WHITE, secondelebtro'n discharge tube.- -BENJAMIN B; HULL.

IRVING LANGMUIR. 1 

